The purpose of this study is to evaluate the preliminary safety and determine the RP2D of mezigdomide in combination with elranatamab in participants with relapsed and refractory multiple myeloma (RRMM).
Age ≥18 with history of relapsed and refractory multiple myeloma (RRMM) treated with 2 to 4 prior lines of anti-myeloma therapy (Phase 1) or 1 to 3 prior lines of anti-myeloma therapy (Phase 2).
Measurable MM by local laboratory.
Eastern Cooperative Oncology Group performance status (ECOG PS) of 0 to 1.
Adherence to contraception requirements.
Prior treatment with mezigdomide.
Prior treatment with T cell engaging or T cell engager (TCE).
Prior treatment with B cell-maturation antigen (BCMA)-targeting therapy, with the exception of participants who have received autologous BCMA-targeted CART-cell therapy> 6 months from the start of study therapy
Other protocol-defined Inclusion/Exclusion criteria apply.